1. Field of the Invention
The present invention relates to an image reproducing apparatus for obtaining a positive reproduced image from a microfilm having a negative or positive image.
2. Description of the Prior Art
In an electrophotographic copying of a microfilm image, an ordinary image development is employed for obtaining a positive reproduced image from a positive microfilm image as shown in FIG. 1A while a so-called reserved development is employed for obtaining a positive reproduced image from a negative microfilm image as shown in FIG. 1B.
The normal development is achieved by charging a photosensitive sheet for example an electrofax sheet having a zinc oxide coating on a substrate in a polarity opposite to the polarity of the toner, and applying said toner onto an electrostatic latent image formed on the photosensitive sheet. On the other hand the reversed development is achieved by charging a photosensitive sheet in a polarity same as that of the toner and applying said toner to an electrostatic latent image formed on said photosensitive sheet. In such conventional electrophotographic apparatus it has been necessary to select the polarity of charging for the photosensitive member according to whether the image on the microfilm is negative or positive. Such polarity selection has been conducted manually by switches after the microfilm image visually identified as positive or negative, but such apparatus has been associated with the troubles of erroneous or forgotten switching.